Fungicidal vinyl 2-substituted-thiovinyl sulfones

ABSTRACT

Vinyl 2-arylthiovinyl and vinyl 2-alkylthiovinyl sulfones, having fungicidal and algicidal activity, are prepared by the addition of arylsulfenyl halides or alkylsulfenyl halides to divinyl sulfone and the dihydrohalogenation of the resulting 1,2-addition product.

This is a division of application Serial No. 657,679, filed February 12,1976, now U.S. Pat. No. 3,988,376.

DESCRIPTION OF THE PRIOR ART

Chemical Abstracts 68 59110t (1968) and 67 108135v (1967) disclose thepreparation of beta-substituted ethyl vinyl sulfones by the addition ofalcohols and mercaptans to divinyl sulfone.

DESCRIPTION OF THE INVENTION

The compounds of the invention are represented by the formula

    RSCH=CHSO.sub.2 CH=CH.sub.2

wherein R is alkyl of 1 to 6 carbon atoms, phenyl or phenyl substitutedwith 1 to 3 of the same or different substituents selected from fluoro,chloro, bromo, nitro or alkyl of 1 to 4 carbon atoms.

Representative alkyl R groups are methyl, ethyl, propyl and hexyl.Representative aryl R groups are 4-chlorophenyl, 2-fluorophenyl,3,5-dibromophenyl, 2-nitro-4-methylphenyl, 4-tolyl,2-chloro-4-methylphenyl, and 2,4,6-trichlorophenyl.

Preferably R is phenyl or phenyl-substituted with 1 to 2 of the same ordifferent substituents selected from fluoro, chloro, bromo, nitro oralkyl of 1 to 4 carbon atoms. Most preferably, R is phenyl substitutedwith 1 to 2 chloro or bromo.

Representative compounds of the invention include:

Vinyl 2-(2-chlorophenylthio)vinyl sulfone,

Vinyl 2-(2-chloro-4-bromophenylthio)vinyl sulfone,

Vinyl 2-(2-methyl-4-ethylphenylthio)vinyl sulfone,

Vinyl 2-(2-methyl-4-nitrophenylthio)vinyl sulfone,

Vinyl 2-methylthiovinyl sulfone,

Vinyl 2-isopropylthiovinyl sulfone, and

Vinyl 2-hexylthiovinyl sulfone.

The compounds of the invention are prepared by adding a sulfenyl halide(II) to divinyl sulfone (III) and dihydrohalogenating the resulting1,2-addition product (IV) with a base to obtain the vinyl2-substituted-thiovinyl sulfone product (I), as depicted in thefollowing reactions: ##STR1## wherein R has same significance aspreviously defined, X is chloro or bromo and B is a base.

Reaction (1) is conducted by reacting substantially equimolar amounts ofthe sulfenyl halide (II) and divinyl sulfone (III) in the liquid phaseat a temperature of about 0° to 100° C. Generally, an inert organicdiluent, such as an alkane, haloalkane or an aromatic compound, isemployed in the reaction. Reaction pressure is suitably atmospheric,subatmospheric or superatmospheric. For convenience, the reactionpressure is generally atmospheric. The reaction is generally exothermicand is completed within about 1 to 24 hours.

In reaction (2), the 1,2-addition product (I) is treated withsubstantially equimolar amounts of a base. The preferred base is anorganic base such as a pyridine compound, e.g., pyridine or analkylpyridine, or a trialkylamine, e.g., triethylamine. Reaction (2) isconducted in the liquid phase at a temperature of 0° to 100° C. Thereaction pressure is not critical, and, for convenience, the pressure isgenerally atmospheric. The reaction is generally complete within about 1to 24 hours. The product (I) is isolated by conventional procedures suchas filtration, extraction, distillation, chromatography, etc.

UTILITY

The compounds of the invention are useful for controlling fungi,particularly plant fungal infections caused by Botrytis cinerea, leafblights caused by organism such as Pythrium ultimum, Helminthosporumsativum, Fusarium moniliforme, Rhizoctonia solani, Monolinia fructicolaand uromyces phaseoli typica. However, some fungicidial compounds of theinvention may be more fungicidally active then others against particularfungi.

When used as fungicides, the compounds of the invention are applied infungicidally effective amounts to fungi and/or their habitats, such asvegetative hosts and non-vegetative hosts, e.g., animal products. Theamount used will, of course, depend on several factors such as the host,the type of fungus and the particular compound of the invention. As withmost pesticidal compounds, the fungicides of the invention are notusually applied full strength, but are generally incorporated withconventional, biologically inert extenders or carriers normally employedfor facilitating dispersion of active fungicidal compounds, recognizingthat the formulation and mode of application may affect the activity ofthe fungicide. Thus, the fungicides of the invention may be formulatedand applied as granules, as powdery dusts, as wettable powders, asemulsifiable concentrates, as solutions, or as any of several otherknown types of formulations, depending on the desired mode ofapplication.

Wettable powders are in the form of finely divided particles whichdisperse readily in water or other dispersant. These compositionsnormally contain from about 5-80% fungicide, and the rest inertmaterial, which includes dispersing agents, emulsifying agents andwetting agents. The powder may be applied to the soil as a dry dust, orpreferably as a suspension in water. Typical carriers include fuller'searth, kaolin clays, silicas, and other highly absorbent, readilywettable, inorganic diluents. Typical wetting, dispersing or emulsifyingagents include, for example: the aryl and alkylaryl sulfonates and theirsodium salts; alkylamide sulfonates, including fatty methyl taurides;alkylaryl polyether alcohols, sulfated higher alcohols, and polyvinylalcohols; polyethylene oxides, sulfonated animal and vegetable oils;sulfonated petroleum oils, fatty acid esters of polyhydric alcohols andthe ethylene oxide addition products of such esters; and the additionproducts of long-chain mercaptans and ethylene oxide. Many other typesof useful surface-active agents are available in commerce. Thesurfaceactive agent, when used, normally comprises from 1 to 15% byweight of the fungicidal composition.

Dusts are freely flowing admixtures of the active fungicide with finelydivided solids such as talc, natural clays, kieselguhr, pyrophyllite,chalk, diatomaceous earths, calcium phosphates, calcium and magnesiumcarbonates, sulfur, lime, flours, and other organic and inorganic solidswhich act as dispersants and carries for the toxicant. These finelydividied solids have an average particle size of less than about 50microns. A typical dust formulation useful herein contains 75% silicaand 25% of the toxicant.

Useful liquid concentrates include the emulsifiable concentrates, whichare homogeneous liquid or paste compositions which are readily dispersedin water or other dispersant, and may consist entirely of the fungicidewith a liquid or solid emulsifying agent, or may also contain a liquidcarrier such as xylene, heavy aromatic naphthas, isophorone, and othernonvolatile organic solvents. For application, these concentrates aredispersed in water or other liquid carrier, and are normally applied asa spray to the area to be treated.

Other useful formulations for fungicidal applications include simplesolutions of the active fungicide in a dispersant in which it iscompletely soluble at the desired concentration, such as acetone,alkylated naphthalenes, xylene, or other organic solvents. Granularformulations, wherein the fungicide is carried on relatively coarseparticles, are of particular utility for aerial distribution or forpenetration of cover-crop canopy. Pressurized sprays, typically aerosolswherein the active ingredient is dispersed in finely divided form as aresult of vaporization of a low-boiling dispersant solvent carrier, suchas the Freons, may also be used. All of those techniques for formulatingand applying fungicides are well known in the art.

The percentages by weight of the fungicide may vary according to themanner in which the composition is to be applied and the particular typeof formulation, but in general comprise 0.5 to 95% of the toxicant byweight of the fungicidal composition.

The fungicidal compositions may be formulated and applied with otheractive ingredients, including other fungicides, insecticides,nematocides, bactericides, plant growth regulators, fertilizes, etc.

The compounds of the invention are also useful for controllingmicrobiological organisms such as algae, bacteria, molds andoccasionally aquatic weeds which foul aqueous industrial effluents andcooling streams, such as those occurring in the paper and foodprocessing industries. They may also be used to control such organismsin other aqueous bodies such as lakes, streams, canals, pools and thelike. When so used, a biocidal quantity of one or more of the compoundsof this invention is added to the aqueous growth environment of theorganisms. Usually, this dosage will range between about 0.1 to 50 ppm.In any given instance, the optimum dosage will depend upon theparticular organism and aqueous body involved. For instance, when usedto control algae, these compounds will usually be employed atconcentrations of about 0.1 to 10 ppm. In terms of pounds of compoundper acre of water one foot deep 0.1 to 10 ppm is equal to about 0.3 to30 pounds per acre of water 1 foot deep. These compounds may be appliedto the aqueous growth environments of such organisms as dispersiblepowders or in solution with water-miscible solvents.

EXAMPLE 1 Preparation of Vinyl 2-(4-chlorophenylthio)vinyl Sulfone

Fifty grams of 4-chlorophenylsulfenyl chloride was added slowly to 33.0g of divinyl sulfone in 150 ml of dichloromethane with cooling to removethe heat of reaction. After a few hours of standing at ambienttemperature, the solvent was stripped and the crude adduct was dissolvedin 200 ml of benzene. Thirty-one g of triethylamine was added slowlywith cooling to maintain ambient temperature. After standing for onehour, the triethylamine hydrochloride was removed by filtration. Afterwashing with water and drying over magnesium sulfate, the solvent wasstripped to give 64 g of crude product. This was purified bychromatography over silica gel to give 48 g of vinyl2-(4-chlorophenylthio)vinyl sulfone; calculated for C₁₀ HgCl0₂ S₂ :S,24.6; found: S, 24.4.

The infrared and NMR spectra support the structure. Thin-layerchromatography on silica gel shows the presence of cis- and trans-isomers as two adjacent spots. The product is tabulated in Table I ascompound No. 1.

EXAMPLE 2 Preparation of Vinyl 2-(4-t-butylphenylthio)vinyl sulfone

In a manner analogous to Example 1, 4-t-butylphenylsulfenyl chloride wasadded in 1:1 proportion to divinyl sulfone, subjected to treatment withtriethylamine in benzene, and purified by column chromatography. Theproduct, vinyl 2-(4-t-butylphenylthio)vinyl sulfone, was obtained as abrown oil which crystallized on standing, m.p. 62°-64° C; calculated forC₁₄ H₁₈ O₂ S₂ :S, 22.7; found: S, 22.0; Cl, 0.

Spectroscopic examination by infrared and NMR are in full accord withthe proposed structure. The product is tabulated in Table I, as compoundNo. 10.

The other compounds tabulated in Table I were prepared by proceduressimilar to that described in Example 1.

EXAMPLE 3 Mycelial Inhibition

A number of the compounds of the present invention were evaluated forfungicidal effectiveness by means of a mycelial inhibition test. Thistest is designed to measure the fungitoxic activity of fungicidalchemicals in terms of their degree of inhibition of mycelium growth.Each compound to be tested was dissolved in acetone to 500 ppmconcentration. Paper strips were innoculated with the particularmycelium growth by covering the paper with a potato dextrose brothculture of mycelial suspension. The innoculated papers were then placedon potato dextrose agar plates and sprayed by means of a micro sprayerwith the fungicidal solution. The treated paper strips were incubated at25° C and data is taken after 24 hours. Fungicidal activities aremeasured by a zone of inhibited mycelial growth from the center of thepaper strip. The effectiveness of the compounds tested for fungicidalactivity is reported in Table II in terms of the microgram/cm² for 99%control of the fungus.

EXAMPLE 4 Algae Control

Representative compounds of the invention were tested as algicides bythe following method. The algae test species were Lemna, Elodea andSpirolina.

An acetone solution of the test compound and a small amount of analkylarylpolyoxyethylene glycol-containing surfactant was prepared. Thissolution was mixed with a nutrient broth in a quantity sufficient togive a concentration of 2 ppm. A 240 ml container was filled with thismixture. A sample of the test algae was added to each container and thecontainer was then placed in an illuminated environment maintained at atemperature of about 20° C for incubation. The containers were observedperiodically for algae growth (as compared to an untreated check). Thealgicidal effectiveness of the test compound was determined based on afinal observation of algae growth after 7 to 10 days. The results of thetest on a 0 to 100 basis -- 0 indicating no effectiveness and 100indicating complete effectiveness -- are reported in Table III.

                  TABLE I                                                         ______________________________________                                        Compounds of the formula RSCH=CHSO.sub.2 CH=CH.sub.2                                           Elemental Analysis                                           Compound          Physical Sulfur   Halogen                                   No.       R       State    Calc.                                                                              Found Calc.                                                                              Found                              ______________________________________                                        1       p-Cl-φ.sup.(a)                                                                      Liquid   24.6 23.5  13.6 13.4                               2       m-Cl-φ                                                                              Oil      24.6 24.2  13.6 14.7                               3       p-Br-φ                                                                              Liquid   21.0 20.7  26.2 28.8                               4       p-CH.sub.3 -φ                                                                       Oil      26.6 24.4  --   --                                 5       2,5-Cl.sub.2 -φ                                                                     Oil      21.7 20.2  24.0 25.5                               6       p-F-φ Oil      26.3 24.1  7.8  8.4                                7       p-NO.sub.2 -φ                                                                       Semi-    23.6 21.9  --   --                                                   solid                                                       8       3,4-Cl.sub.2 -φ                                                                     Oil      21.7 20.9  24.0 26.2                               9       φ     Oil      28.3 25.9  --   --                                 10      p-(t-C.sub.4 H.sub.9)-φ                                                             m.p.     22.7 22.2  --   --                                                   62-64° C                                             11      CH.sub.3  Oil      39.0 40.5  --   --                                 ______________________________________                                         .sup.(a) φ represents phenyl                                         

                  TABLE II                                                        ______________________________________                                        Mycelia Inhibition, microgram/cm.sup.2 for 99% control                                         Rhiz-   Asper-                                               Compound                                                                              Pythium  octonia gillus                                                                              Fusarium Botrytis                              No.     Ultimum  Solani  Niger Moniloforma                                                                            Cinerea                               ______________________________________                                        1       0.24     0.8     0.6   1.5      0.98                                  2       >1.7     0.7     0.8   1.1      0.34                                  3       >1.7     0.85    1.1   0.78     0.69                                  4       0.67     >1.7    0.68  0.68     0.83                                  5       >1.7     1.3     >1.7  >1.7     0.67                                  6       1.1      0.76    0.47  1.5      1.0                                   7       0.82     0.37    1.5   1.6      0.80                                  8       0.86     0.95    0.57  >1.7     0.87                                  9       1.1      0.6     0.88  >1.7     0.56                                  10      >1.7     0.65    0.88  1.1      >1.7                                  11      1.6      >1.7    >1.7  >1.7     1.6                                   ______________________________________                                    

                  TABLE III                                                       ______________________________________                                        Percent Aquatic Weed Control                                                  Compound                                                                      No.         Lemna     Elodea    Spirolina                                     ______________________________________                                        1           100       100       --                                            2           100       99        100                                           3           99        90        100                                           4           100       96        90                                            5           90        78         0                                            6           100       100       80                                            7           99        100       50                                            8           90        90         0                                            9           94        70        40                                            10          22         0        40                                            11          100       70        70                                            ______________________________________                                    

What is claimed is:
 1. A method for the control of fungi which comprisesapplying thereto a fungicidally effective amount of a compound of theformula

    RSCH=CHSO.sub.2 CH=CH.sub.2

wherein R is alkyl of 1 to 6 carbon atoms, phenyl or phenyl substitutedwith 1 to 3 of the same or different substituents selected from thegroup consisting of fluoro, chloro, bromo, nitro and alkyl of to 4carbon atoms.
 2. The method of claim 1 wherein R is alkyl.
 3. The methodof claim 1 wherein R is methyl.
 4. The method of claim 1 wherein R isphenyl or phenyl substituted with 1 to 2 of the same or differentsubstituents selected from the group consisting of fluoro, chloro,bromo, nitro and alkyl of 1 to 4 carbon atoms.
 5. The method of claim 1wherein R is phenyl substituted with 1 to 2 chloro or bromo.
 6. Themethod of claim 1 wherein R is p-chlorophenyl.
 7. A fungicidalcomposition comprising a biologically inert carrier and a fungicidallyeffective amount of a compound of the formula defined in claim
 1. 8. Thecomposition of claim 7 wherein R is alkyl.
 9. The composition of claim 7wherein R is phenyl or phenyl substituted with 1 to 2 of the same ordifferent substitutents selected from the group consisting of fluoro,chloro, bromo, nitro and alkyl of 1 to 4 carbon atoms.
 10. Thecomposition of claim 7 wherein R is phenyl substituted with 1 to 2chloro or bromo.
 11. The method of claim 1 wherein R is3,4-dichlorophenyl.